Solve for $n$ : $-11 + n = -13$
Explanation: Add $11$ to both sides: $ \begin{eqnarray} \\ -11 + n &=& -13 \\ \\ {+11} && {+11} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{-11 + n} &\hphantom{=}& \hphantom{-13} \\ n &=& -13 {+ 11} \\ \end{eqnarray} $ Simplify. $ n = -2$